Lotion pumps have already been widely used in the industries of chemical articles for daily use and medicine. In the conventional lotion pumps, the container cap and the housing cap are separately arranged. In order to further reduce the cost and to make the manufacturing and installation more convenient, the inventor of this application filed an application titled “Multi-Functional Lotion Pump” with the CPO in Mar. 29, 1999, and being patented as ZL99207292.1. In the multi-functional lotion pump, the container cap is integrated with the housing cap and the number of the injection molded parts is reduced to four, thereby the manufacturing cost is greatly reduced, and the requirement on engagement between the parts are minimized.
However, in the above mentioned multi-functional lotion pump, some problems are still to be resolved.
Firstly, it is difficult to accomplish the orientation. In the conventional lotion pump, in which the container cap and the housing cap are separately arranged, when the container cap is not screwed tightly, the container cap and housing cap can be rotated relatively. Therefore, when the lotion is filled at the factory, the nozzle of the spray head can be turned to a desired angle, and after the container cap is screwed tightly, the direction of the nozzle is also fixed in the desired direction. However, in the above-mentioned multi-functional lotion pump, because the housing cap and the container cap are integrated with each other, it is impossible to use the above-mentioned method to adjust the direction. Hence, for the same lotion pump, if it is used in container bottles with different heights of mouth, the direction of the nozzle will be different. For the same container bottle, if different lotion pumps are used, it is possible that the directions of the nozzles will be different. In addition, the heights of the two sets of screw teeth of the nozzle head and of the housing cap should be identical at the stop position, which will render much difficulty to the manufacturing of the mold and the process control. Even the above-mentioned precision can be reached, it is needed to increase the precision requirement on the mouths of the container bottles to guarantee the consistency of the heights of the mouths.
Next, the spring with varying diameters cannot guarantee the sealing performance of the lower ball. In the above-mentioned multifunctional lotion pump, the sealing of the nozzle, when the nozzle head is locked, is realized by pressing the spring with varying diameters onto the lower one-way valve ball. This makes higher demands on the compression degree and the coaxiality of the spring, the height and the diameter of the spring at the portion with the thinnest diameter, and the height of the ball support. If these demands are not satisfied, it is difficult to realize the reliable sealing.
Furthermore, too much screw threads and the spring with varying diameters would increase the manufacturing cost. The nozzle head of the above-mentioned multiple-functional lotion pump has one set of screw teeth, the container cap has three sets of screw teeth. The production cycle of such screw threads is relatively longer, some complex molds have to be used, and the mounting and engagement of two sets of screw teeth takes more time, thereby not favorable to the production in large batches and to reach high efficiency. In addition, the quantity of raw material to be used for the spring with varying diameters is rather high, and the cycle for manufacturing is rather long, leading to a relatively high cost.
Finally, the structure of the valve seat of the upper one-way value is rather complex. In the above-mentioned multi-functional lotion pump, the valve seat of the upper one-way valve is disposed within the plunger, forming a “V” structure. This valve seat structure makes the mold design and the entire molding process complex, and makes the resistance in the passage for lotion relatively large.